Spark plug



Sept. 23. 1924 P. B BURHANS 'SPARK PLUG Original Filed Feb. 21. 1925 VII/4711 Patented Septi 23, 1.924,

UNITED STATES PAUL B. BUEHAINS, OF SANFORD, FLORIDA.

SPARK PLUG.

Application filed February 21,1920, Serial No. 360,2?1. Renewed February 25, 1924.

To all whom it may concern:

Be it known that 1, PAUL B. BURI-IANS, a citizen of the UnitedSta-tes, residing at Sanford, in the county of Seminole and State of Florida, have invented a new and useful Spark Plug, of which the following is a specification.

This invention relates to new and useful improvements in spark. plugs adapted for use in connection with internal combustion engines and the object thereof is to provide an improved construction and sparking arrangement for a plug of the multiple spark type to produce a larger and more enduring flame than heretofore, without materially increasing the power or the electro-motive force of the source of current supply.

A further object of the invention is to provide a spark plug having multiple or plural spark points so arranged as to allow for the decreasing strength of the current as the spark gaps are bridged by the sparks produced, so as to increase flame propagation and facilitate combustion of the compressed gases throughout the stroke of the piston.

A further object of the invention is to arrange the positive electrode in a novel relation to the points, which latter are constructed in a novel manner in conjunction with the porcelain or other insulated bushing whereby to prevent short circuiting of the casing or shell of the plug, and to so construct the device, as to form a gas pocket or cavity to facilitate combustion.

With the above and other objects in view which will appear as the description proceeds, the invention resides in the combina tion and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that within the scope of what is claimed, changes in the precise embodiment of the invention shown can be made without departing from the spirit of the invention.

In the accompanying drawings:

Figure 1 is a vertical sectional view of my improved spark plugtaken on the line 1--1 of Figure'Q, and looking in the direction indicated by the arrows;

Figure 2 is a bottom view;

Figure 3 is an enlarged. view of the positive electrode;

Figure 4; is an enlarged sectional view of a fragmentary portion of the core with a point mounted therein; and

views, my improved spark plug is shown as P comprising the usual conducting shell or casing 10 which includes an externally threaded lower section 11 and an upper sec tion 12 provided with a circumscribing reduced portion or shoulder 13 adapted to conform to the shape of the porcelain or other insulating bushing 14: which is mounted within. said shell or casing. This bushing has the stem 15 and is formed with a circumscribing shoulder or rib 16 the bottom face of which is adapted for contact with the upper end of the attaching portion or lower section 11, there being interposed h'etwcen the faces, a washer or other packing gasket 17 in order to prevent breakage as wellas to close the joint between the bushing and the shell of the plug.

There is disposed between the end portion 13, which is cut on two arcs concentric to the center of the plug, and the upper end of the rounding shoulder 16, a packing washer or gasket 18 in order to further insure against the breakage and escape of gases between the bushing and shell. The lower portion of the bushing is smaller than the interior diameter of the section 11 of the shell to provide an annular space or chamber 19, said bushing extending below the lower end of the lower section of the plug as indicated, and being provided with a concavity or recess 20 axially of the bottom or lower end thereof, to form a gas pocket, as will be further explained.

The positive electrode is indicated at 21,

the same passing axially through the stem portion 15 of the bushing and terminating in a binding out or terminal 22, while below the upper face of the shoulder 16, the electrode or conductor, is extended outwardly at an obtuse angle, so as to pass diagonally through the main portion of the bushing and to project from the lower annular portion'thereof around the concavity or recess 20, where it is formed with an inwardly extending sparking point 23 as shown.

The negative electrode which is anchored to the shell creasing, is indicated at 2 4,the same having an inwardly directed sparking point 25 located below the projecting end of cor 0 bush ng- A ranged in a circ e 0 .11--

centric to the axis of the plug, is a plurality of sparking points 26, the same having their upper ends 27 so formed as to prevent loosening or displacement of the points after being embedded in the porcelain or other insulator formed by the bushing or core, preferably when the latter is in a green or plastic shape. The lower ends thereof as indicated at 28, are tapered toward their ends to form effective sparking points and beginning at the positive electrode or point 23,and approaching the negative electrode or point in the series, the said points are consecutively placed at closer relation or at decreased distances from each other, so thatthe effective spark gaps between the points are decreased, thereby decreasing the resistance offered to the passage of the spark, and the electro-motive force sufficient to overcome or break down the intervening air resistance, in order that a relatively strong but somewhat broken sparking flame is produced, without necessarily being continuous. By the use of the anchor points, they are maintained free from oil or soot [collecting thereon, and the spark willjump more easily between the points than from a ball or square body. Furthermore, by having the positive electrode and point disposed concentrically of the plug at one side, it is possible to produce a circle of fire as the spark jumps each gap. The points are also securely '5 anchored in the porcelain or other nonconductor forming the core and expansion of the porcelain will not loosen them, thus maintaining the shank portion of the points firmly fixed in position.

It will also be seen, that by arranging the points in the manner specified, the gap between the points is made shorter from the positive to the negative pole or electrode, thus lessening the resistance as the current passes through and as the current becomes weaker. By this sparking arrangement, in

' conjunction with the recess or concavity in the center of the porcelain body or core, said cavity being preferably bell-shaped, and arranging the points around the concavity, as clearly shown and described, when the piston is compressing the fresh charge of gas, this chamber or concavity fills with gas and when ignited, the explosion forces the burned gases with violence past the points ,of the plug, thus tending to keep them clear and carbonless.

' It will thus be seen that I have provided means for producing a plurality of sparks for each ignition, the sparking points being so arranged as to permit the proper use of a relatively small current Without failing in sparking, to so form the sparking points that they will become self-cleaning, and

also' to make the conducting-bodies which have the sparklng-points of the interch angeable form and shaped for mounting in the insulation so that the expansion of the latter by heat will not permit the points to loosen, interfere with or result in derangement of the sparking system. \Vhile I have described a particular construction of shell, it is also to be understood. that a construe tion there may be varied as desired and that the sparking heads constituting the anchor ends consists of conducting bodies, each body being double ended or double headed and diminishing in size medially, with the heads or ends preferably of the same size and shape so as to be reversible and interchangeable one for another. Also, as particularly shown in Figure 4 of the drawings, one head is embedded in the substance of the insulating core and the other head outside and spaced from said core to extend downwardly therefrom, the points being oppositely tapered at the heads thereof, in order to effectively convey the current and insure bridging of the gaps to produce the sparks. Also, while I have shown a plurality of the bodies constituting the points 26. between the terminals or electrodes 23 and 25, yet it is obvious that but one body may be positioned between said terminals to provide but two sparking gaps therebetween and. that they may be arranged in any number and in any desired alignment, straight, or otherwise, but preferably circularly and eccentrically as described, to permit of any desired plurality being used. The bodies are so arranged relative to each other as to produce a progressively decreasing length of spark gaps between them, the oppositely directed sparking points of said bodies being so positioned as to deliver between the bodies next succeeding them throughout the series. thus producing a. most effective delivery of electric current from one to the other and with the least possible resistance as well as compensating for the resistance of the conducting bodies which increase as the number of said bodies increase while allowing for the decrease in the strength of the current.

Having thus described the invention what I claim is:

1. In a spark-plug having spaced terminals, one insulated from the other, a conducting-body positioned between the terminals, said conducting-body having like enlarged heads on its opposite extremities, one head being embedded in insulation, the heads having current-transmitting points directed respectively toward said terminals.

2. A spark plug comprising a casing; 11 bushing in the casing; an electrode mounted in the bushing; an electrode carried by the casing; and a member carried by the bushing and including a transverse conducting foot disposed between the electrodes, the foot being tapered from its intermediate portion to its ends, and being inclined, from its intermediate portion to its ends, toward the bushing.

3. A spark plug comprising a casing; a bushing in the casing; an electrode mounted in the bushing; an electrode carried by the casing; and a conducting member embodying a shank and identical transverse heads at the ends of the shank, each head being tapered from its intermediate portion to its ends, each head comprising angularly disposed parts defining a point alined with the shank, one head and a portion of the shank being embedded in the bushing, the other head being exposed and being located 15 between the electrodes.

In testimony that I claim the foregoing as my own, I have hereto affixed my signature in the presence of two witnesses.

PAUL B. BURHANS. Witnesses R. L. FINLEY, J. W. HARDMAN. 

